The news could have big implications for Twitter, which last night announced that it had filed for an initial public offering. The social media network's success as a public company will hinge in large part on its ability to be successful with real-time advertising products, not unlike the promoted tweets the Twitter appears to have been sending certain users.

However, sending such push notifications could be against Apple's developer rules, which prohibit the use of push notifications to send "advertising, promotions, or direct marketing of any kind."

We reached out to Twitter for this story, and we'll update if and when the company responds.